LifeVest wearable defibrillator reduces total mortality after cardiac revascularisation, study shows


Zoll Medical announced that a study demonstrating a reduction in total mortality after cardiac revascularidation in patients prescribed a LifeVestwearable defibrillator was presented at the American Heart Association’s Scientific Sessions 2011 in Orlando, USA.

Edwin Zishiri, Cleveland Clinic, presented an abstract entitled “Use of the wearable cardioverter defibrillator and survival after coronary artery revascularisation in patients with left ventricular dysfunction.” The analysis sought to determine if there is a difference in survival of patients with a left ventricular ejection fraction less than or equal to 35% (LVEF≤35%) using the LifeVest following surgical or percutaneous revascularisation (CABG or percutaneous coronary intervention (PCI), respectively) compared to patients discharged without the LifeVest. Kaplan-Meier survival, Cox proportional hazards and propensity score matched analyses were performed to determine if survival differed in patients discharged after CABG or PCI revascularisation with LVEF≤35% from a national database of LifeVest patients (N=809) compared to non LifeVest patients from registries at the Cleveland Clinic (N=4,149).

Survival curves showed an 80% reduction in total mortality at 90 days for LifeVest patients as compared to non LifeVest patients post percutaneous coronary intervention, with 90 day mortality of 2% for LifeVest patients versus 10% for non-LifeVest patients. In addition, LifeVest use was associated with an adjusted 57% lower risk of death in post percutaneous coronary intervention patients (p<0.0001) over a mean follow up of 3.1±2.3 years. Survival curves showed a 57% reduction in total mortality at 90 days for LifeVest patients as compared to non LifeVest patients post CABG, with 90 day mortality of 3% for LifeVest patients versus 7% for non LifeVest patients. In addition, LifeVest use was associated with an adjusted 38% lower risk of death in post CABG patients (p=0.048) over a mean follow up of 3.2 ± 2.5 years. In summary, LifeVest patients experienced a reduction in total mortality at both 90 days and 3 years as compared to the non LifeVest patients after cardiac revascularisation.

“Patients with a low ejection fraction after a PCI or CABG have a high risk of mortality in the first 90 days following the procedure, with up to 60% of this mortality due to sudden cardiac death,” said Richard A. Packer, Zoll’s CEO. “These powerful data demonstrate that the LifeVest significantly reduces total mortality in these high risk patients during recovery following a revascularisation. It is equally, if not more, remarkable that these data show the LifeVest reduces three year mortality, with continuing separation of the survival curves over the long-term. LifeVest is commonly worn by patients for 90 days following a PCI or CABG, and the fact that the mortality benefit of LifeVest extended beyond the time patients typically wear the device may indicate potential clinical benefits related to optimisation of medical therapy, patient compliance with prescribed treatment and follow-up, along with other broad healthcare impacts.”

About LifeVest

The LifeVest is worn by patients at risk for sudden cardiac arrest, providing protection during their changing condition and while permanent sudden cardiac risk has not been established. The LifeVest allows a patient’s physician time to assess his or her long-term arrhythmic risk and make appropriate plans. The LifeVest is lightweight and easy to wear, allowing patients to return to their activities of daily living, while having the peace of mind that they are protected from sudden cardiac attacks. The LifeVest continuously monitors a patient’s heart and, if a life-threatening heart rhythm is detected, the device delivers a treatment shock to restore normal heart rhythm.

The LifeVest is used for a wide range of patient conditions or situations, including following a heart attack, before or after bypass surgery or stent placement, as well as for those with cardiomyopathy or congestive heart failure that places them at particular risk.